namespace Components {
  // 命名空间内的子命名空间
  export namespace SubComponents{
    export class Test {}
  }

  // 命名空间内导出接口
  export interface user {
    name: string;
  }

  export class Header {
    constructor() {
      const elem = document.createElement('div');
      elem.innerText = 'This is Header';
      document.body.appendChild(elem);
    }
  }

  export class Content {
    constructor() {
      const elem = document.createElement('div');
      elem.innerText = 'This is Content';
      document.body.appendChild(elem);
    }
  }

  export class Footer {
    constructor() {
      const elem = document.createElement('div');
      elem.innerText = 'This is Footer';
      document.body.appendChild(elem);
    }
  }
}
